Solar Panel - how many watts is it?

Discussion in 'Solar Power' started by RowleyBirkinQC, Feb 25, 2015.

  1. RowleyBirkinQC

    RowleyBirkinQC Funster

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    Apologies if this is a silly question due to my ignorance! The van we bought second hand last autumn came with a solar panel already installed. I'm contemplating whether we should fit a second solar panel in case we do more wild camping / stay at sites without EHU etc.

    With this in mind, is there a way to easily identify the wattage of the existing panel? Would the wattage of the existing panel in anyway influence or dictate which second panel should or could be installed?

    Thanks in advance for any pointers!
     
  2. Baycott

    Baycott Funster

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    No question is silly on here. There is usually someone else that would like to know the answer but hasn't got round to asking.
    That's me so I will be following this thread with interest. (y)
     
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  3. Techno

    Techno Funster Life Member

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    How long x how wide?
     
  4. Reallyretired

    Reallyretired Funster

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    Regardless of the wattage of your existing panel, it has no bearing on the wattage of any other panel you add. Add whatever you like.
    The size of the panel will give a good idea of the wattage.
     
  5. laurieash

    laurieash Funster

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    Do not agree with the above as if its 100w pannel and you add another 100w it can over load say a sargent system which states 120w max.
     
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  6. RowleyBirkinQC

    RowleyBirkinQC Funster

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    Thanks for the feedback, looks like I need to get the ladder and a tape measure out as a start then... (y)
     
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  7. Wickolad

    Wickolad Funster

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    If you have a small inspection mirror, try to look on underside of panel, there is often a spec label stuck there. Usually just below terminal box. Just read it in reverse, you'll either have WOOl, WOB or WOd ish haha. (y)
     
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  8. emmitdb

    emmitdb Funster

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    And as Laurieash alluded to, we need to know the size of the regulator, (small box that has connections from the existing panel to the batteries.) Should have the 'ampage' written on it.

    Sorry in advance for dumbing down my comments but I/We don't know your knowledge.
     
  9. Encantador

    Encantador Funster

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    Hope OP does not mind me butting in. I am in exactly the same situation, existing panel is 120cm x 32cm. Pic of the regulator below.

    Solar Reg.jpeg
     
  10. Lenny HB

    Lenny HB Funster

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    Not a very common size but by surface area I would guess at around 50 watts, also depends on type for a given output a Polycrystallinewill be larger than a Monocrystalline panel.
     
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  11. Encantador

    Encantador Funster

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    Thanks, so not very big then.

    Can a second panel be fitted (plenty of roof space) and fed into the same regulator?
    If it can, what would be a good size to go for and where from?

    I have been quoted £75 (3 hours labour) just to fit, does that sound about right?

    Thanks
     
  12. Lenny HB

    Lenny HB Funster

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    Are you sure your sizes are right 120x32 is 47" x 12½".
    Labour rate sounds cheap most dealers charge at least £40 hour, I would expect them to couple the cables with MC4 connectors on the roof so shouldn't take that long, 1 - 1½ hours.

    Your regulator is only 6.5 amps so you would need a new regulator, in bright sunlight a 100W panel can get up to 5.5 amps approx.
     
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  13. eddievanbitz

    eddievanbitz Trader - Funster

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    You will need to ensure that the wire from the regulator to the leisure batteries is also up to the job, otherwise your wasting your money on the additional panel.

    A good analogy is always water! Imagine a the biggest supermarket that you have ever been in!

    Now imagine the surface area of the roof!

    Now imagine that the roof is slightly sloped to the middle

    Now imagine that it is raining, heavily!

    Now imagine that there is a massive drain pipe in the middle of the sloping roof to take all of the water

    Now imagine the diameter that pipe would need to be to handle that amount of water

    Now imagine, instead of that huge pipe, replacing it with the down pipe on your house or bungalow :Eeek:

    It would work, but not very well!

    And that is why cable length and diameter are inportant.
     
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  14. Lenny HB

    Lenny HB Funster

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    Ref: to Eddies comment about cable looking at your photo, whoever installed your panel looks like the have used 1.25 or 1.5 mm sq mains cable, that would need replacing with at least 4 mm sq. cable.
     
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  15. Encantador

    Encantador Funster

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    Thanks, so clearly going to be more expensive than it might have been.

    can anyone give me a idea of a good regulator.

    Thanks
     
  16. funflair

    funflair Funster Life Member

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    Might as well get a new regulator to take how ever many panels you want, fit a MPPT and get 25 to 30 % more power, I did a test with two systems wired and the old sunsaver was 25 or 30% behind my new Votronic MPPT, changed it to another Votronic MPPT and now they match each other amp for amp.

    Votronic told me if the panels are different put them on a separate controller.
     
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  17. pappajohn

    pappajohn Funster Life Member

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    Torch and a hand mirror.

    It will have a data label underneath near the wiring terminal box

    Oops...just seen wickolad's post.
     
  18. Encantador

    Encantador Funster

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    Does this mean leaving the panel and regulator I already have and adding a new regulator for the new panel? I assume both regulators can then feed the same leisure batteries?

    Thanks
     
  19. Lenny HB

    Lenny HB Funster

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    Better to replace the regulator, output of two regulators coupled togther will cause problems. Also has the added advantage you only need to run one set of cables down from the roof.
     
  20. Taran_Las

    Taran_Las Funster

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    This what I use. Very happy with its performance (100+50 watt solar panels).
    This would replace your existing controller and allow another panel (or two).
     
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